SinoDefence Forum

PiSigma

from a physics point of view, a cannon would work. but to fire a single shell or projectile, a large of amount of energy would be needed to keep the cannon in place. remember Newton's third law of motion --> "for every motion, there's an equal and opposite reaction." or like some engineers like to say "for every motion, there's an equal and opposite government policy". but back to physics. that means to fire the shell forward toward earth, you need the cannon itself move back toward outer space with the same acceleration as a function of its mass. F=ma. and it order to keep that cannon in the same location in space, you'll need a rocket or booster to constantly pushing on the cannon to adjust itself so that it doesn't fly into outerspace. and that fuel for boosters will be expensive and hard to ship up, and needs a lot of it if considerate damage is needed by the cannon.
also cannons currently depend on gunpowder. now gunpowder is just a chemical compound that's extremely explosive or from a chemical point of view, oxidizing. which means oxygen is required for it work. i'm not a artillery man, ask Golly. but from theory, if there's no oxygen, your cannon is good as useless. and oxygen is just one of those things missing in outer space.
also the earth's atmosphere is very good at melting things at reentry. so you get a small shell, chances are by the time it reaches the ground it would already by burned into its fundamental elements. so no damage could be done. unless you can thrown something the size of a building onto the planet.
of course other oxidents are also used, ammonium nitrate and potassium nitrate. but still need the oxygen to get it all started as far as i know

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darth sidious

that cannon has it own oxygen supply so that wont be a problme also the whole system is a experiment and incredible crude also the target would be American satellites so the melting paart is not a problem




"Use your aggressive feelings boy... let the hate flow through you."

PiSigma

once again, i'm going to go back to fundamental sciences to answer your question.
1 C(s) + 1 O2(g) --> 1 CO2(g)
that means for every mole of carbon combusted, one mole of oxygen is needed.
this is a unbalanced equation of the reaction of potassium nitrate with sulfur, notice that there's much more than just boom sound involved.
KNO3(s) + C(s) + S(s) -----> N2(g) + CO2(g) + K2S(s)

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darth sidious

as I menationed before the whole thing was a experiment altho a dummy satellite was destoryed nothing more was head from them later on the cannon was dismontaled the thing probely dident work well or the russian wondent have signed the treaty you dont need uch pulposion beaqcuse you just have to put the shell in odrite to collide with the target



"Use your aggressive feelings boy... let the hate flow through you."

walter

Anyone here heard of 'rods from God'? It is an idea to simply "drop" tungsten (will not melt in reentry) rods from orbit on any target of interest. Darth sidious said the supposed russian cannon would be used for attacking other sattellites, not for firing earth bound rounds, so such a system would require some sort of propulsive force, ie an explosive chemical reaction. If however, one wants to rain shells or ordance on earth, no need for the gunpowder. Just a small force to push the projectile in the right direction will lower its energy enough to fall back to earth. A tungsten rod "dropped" from space will have more kinetic energy upon impact of the earth's surface than any artillery shell or guided missle in today's arsenals--the destructive force would be scary.

Anyway, let's hope no one deploys those since it would just cause another huge arms race, but there are some very interesting ideas for the weaponization of space.

MIGleader

as a matter of fact...a 23 mm cannon couled be fired, and it would fly forever in space until it hit something, or got sucked in by a gravitational force. as long as the opearting mechanism was actually in a pressurized cabin, a gun could fire in outer space.

Dongfeng

Since ChinaWhite has provided evidence, I have unlocked the thread for further discussion

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Fairthought

It seems several posters owe Darth Sidious an apology. The Soviet Union did indeed test a 23 mm cannon on board an orbiting military space station. Here is the website:

http://www.astronautix.com/craft/almazops.htm


here is a quote from that rather long article:


farther down in the article:


It is also funny that someone would mention 'rods from God', as this was also a real space weapon program explored by the US during the 1990's. Information on this is highly confidential. No word on whether it is actually operational. Of course, the US government will refuse to confirm its existence.

chinawhite

Anyone think china will develop battleship style space stations? Is sapce really the final frontier?.

here is some information i compiled at some random sites

Russian
23 mm/71.7 (0.91") VYa
145.5 lbs. (66 kg)
With a muzzel velocity of
2,985 - 3,020 fps (910 - 920 mps)
thats just over mach 4!
The craft could use the guns AS thrusters!

Russian
23 mm (0.91") AN-23



These guns were gas-operated and belt-fed.
The barrel was monoblock with a blade type breech.
The systems was controlled by Ksenon-125 radar.

So I see no reason why it would require manual aiming.
The only manual operation would be the correction of
alignment from shots, and the stabalizers would be
working overtime just to keep the craft stable.
Another reason I don't see this working.

Picture



The above weapon, is one used on craft.

I didn't see anything like the such mounted
on the orbital craft. If it is armed they hid
that monster of a weapon well.

Link

Salyut 3



11.61 meters long and had a
maximum diameter of 4.15 meters.
Its useful volume totaled 47 cubic meters.

Though some science research was done, the station was
primarily used for military reconnaissance work.
Pavel Popovich, commander of the July 1974 Soyuz 14
flight to Salyut 3, is said to have indicated that the
cannon was installed on Salyut 3 but "fortunately he
was not forced to use it".

Link

Salyut 5
Was structurally similar to Salyut 3 and shared the
same official objectives -- test spacecraft systems,
design and equipment and conduct scientific and technological
research and experiments.
Included two solar panels laterally mounted to its center
and a detachable recovery module for returning data and
materials to the ground. Film could be developed and
analyzed in space and returned in the reentry capsules.

Both of their orbits decayed, and they re-entered the atmosphere.

Here is a website with technical details
http://www.svengrahn.pp.se/histind/A...-%20Salyut%205

End Note

Does china really need to protect her space ships with these cannons. Is america going to abide by her treaties signed with the former soviet union.

China at this momment is still a long way behind in space technology but if the PLA sees it in their interest to have weapons in space it will get weapons in space.

PS: Nice link Fairthought


Regards,

chinawhite

T-U-P

just a question: would the shell or the projectile actually make it to earth? wouldn't it melts completely while entering the atmosphere?

is so, then the purpose of having a cannon on a satellite is only to destroy other satellites, which is not worth it's cost IMO.

FriedRiceNSpice

A cannon would not work without air, since air is needed to create the explosion/expansion that propels the projectile. Also, the recoil in space would actually move the spacecraft it is attached to, making aiming very, very difficult.

chinawhite

This is Not A earth attacking cannon. but a "self-defense" cannon againest other satellites.

The gun is gas powered. THe cannon is attached inside of the space capsule with air. You you guys ever seen a low recoil cannon?. They make a 155mm with minimal reoil.

I must repeat this again. The russians have tested a cannon on the salyut 3 and Sucessfully hit a target. enough said

Regards,

chinawhite

MIGleader

i think the actual action, breech, bolt... of the gun are inside the sattelite. perhaps the barrel is sealed off from ouyter space until the gun is fired.

what i dont know is how the sattelite resists the force of the bullet once fired. once the bullet leaves the barrel, shouldnt its velocity suddenly be split with the sattelite, forciung the sattliet back at 500m per second?

walter

not the velocity, but the impuls: mass x velocity. So a multi ton sattelite firing a projectile of a few kilos wouldn't shoot back at the velocity of the projectile but would recoil with the same impulse of the projectile. It could easily correct this with thrusters.

MIGleader

i think its kinetic energy. for ever action, there is an equal and opposite reaction. in space, theres no inertia to stop a multi ton satteite from spinning off from the impact of a force. think of it as if you were on skakes on an ice rink. if you pusjhed something smaller than you, youd still get puched back quite a bit, although gravity would have an effect still.